Polyester fiberfill is used commercially in many garments and other articles, such as sleeping bags, cushions, comforters and pillows. A particularly useful and desirable form of polyester fiberfill has a coating of cured polysiloxane, often referred to as silicone slickener, e.g. as disclosed in Hofmann U.S. Pat. No. 3,271,189 and Mead et al. U.S. Pat. No. 3,454,422, because certain desirable properties, such as hand, bulk-stability and fluffability are improved thereby. Despite the widespread commercial use of such silicone-slickened-polyester fiberfill, it has long been recognized that this coating has an important disadvantage, together with the desirable qualities. As reported by Pamm U.S. Pat. No. 4,281,042 and Frankosky U.S. Pat. No. 4,304,817, a silicone coating makes it almost impossible to bond the polyester fiberfill at cross-over points, especially when blends of only slickened polyester fiberfill and binder fiber are heat-treated, so as to activate the binder fiber. Any bonds are very poor and seem to be the result of bonding between residues of any binder fibers that were bicomponent fibers, whose cores remain after bonding. Thus it is not practical to use such silicone-slickened fiberfill to form a through-bonded batt or molded article that is properly bonded and durable, as is desirable in some end-uses.
The main object of the present invention is to provide a properly through-bonded batt having advantages of the type that have been obtainable previously only from unbonded slickened materials, e.g. in hand, in combination with the improved performance (especially durability) that has only been attainable previously with bonded batts from "dry" fiberfill. Another object is to improve the resilience and structure stabilization of slickened fiberfill products. Other objects will appear hereinafter.
Reference is made here to Jayne et al. U.S. Pat. No. 3,702,260. Jayne discloses surface-modified polyester fiberfill products having improved compressional recovery and other outstanding properties (see paragraph from column 2-column 3) and to a method for providing such fiberfill products. The coating is co-crystallized on the surface of the crimped polyester staple fiber, and consists of a copolyester comprising about 20-95% by weight of poly(oxyalkylene) units and about 80-5% by weight of ester units identical to those present in the polyester staple fiber substrate. Batts of such coated fibers may be bonded or unbonded and are preferably unbonded (column 2, lines 57-59). Bonding resins may be applied to the batts to prevent any later fiber leakage and/or to prevent shifting of the batting in end-use applications, e.g. by spraying on both sides of the surface in the form of water emulsions, followed by drying and curing (column 5, lines 15-21). Jayne does not mention binder fibers, and Jayne's fiberfill has not been used commercially, so far as is known.